The invention relates to the use of the known compound 2-(2-trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one of the formula (I) shown belowxe2x80x94alias 4,5-dihydro-3-methoxy-4-methyl-5-oxo-N-[[2-(trifluoromethoxy)-phenyl]-sulphonyl]-1H-1,2,4-triazol-1-carboxamide (CAS-Reg.-No.: 145026-88-6)xe2x80x94and its salts, in particular its sodium salt (CAS-Reg.-No. 181274-17-9), for the selective control of weeds in crops of useful plants, in particular for controlling problematic weeds in cereals.
Substituted phenylsulphonylaminocarbonyltriazolinones such as, for example, the compounds 2-(2-trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-ethyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one, 2-(2-trifluoromethoxy-phenyl-sulphonylaminocarbonyl)-4-methyl-5-ethoxy-2,4-dihydro-3H-1,2,4-triazol-3-one, 2-(2-trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-methoxy-5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one, 2(2-trifluoromethyl-phenylsulphonylamino-carbonyl)-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one and 2-(2-di-fluoromethoxy-phenylsulphonylaminocarbonyl)-4-methyl-4-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one and their salts, processes for preparing these compounds and their use as herbicides are the subject of earlier patent applications (cf. EP-341 489, EP422 469, EP-507 171, U.S. Pat. No. 5,534,486). The individual abovementioned substituted phenylsulphonylaminocarbonyltriazolinones have a molecular structure which is very similar to that of the compound (I) to be used according to the invention but, in contrast to this compound, they show shortcomings in their activity or activity gaps in the case of certain weeds.
Surprisingly, it has now been found that the compound 2-(2-trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-methyl-5-methoxy-2,4dihydro-3H-1,2,4-triazol-3-one (I) and salts thereof, in particular the sodium salt of the compound of the formula (I), in comparison with the abovementioned structurally similar compounds, show considerably stronger activity against some weeds in cereal crops which are difficult to control, combined with very good compatibility with cereal species, such as, in particular, wheat, and are therefore particularly suitable for the efficient and selective control of weeds in cereals, in particular in wheat. The activity gaps observed with the abovementioned comparative compounds which are closely related to (I) do not occur in the weed spectrum of the compound (I) and its salts.
The invention provides selective-herbicidal compositions, characterized in that they contain an effective amount of the compound 2-(2-trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one of the formula (I) 
and/or of salts of the compound of the formula (I), in particular of their sodium salt [referred to as xe2x80x9c(I)-Na-saltxe2x80x9d in the use examples].
The invention furthermore provides the use of the compound 2-(2-trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one of the formula (I)xe2x80x94abovexe2x80x94and/or of salts of the compound of the formula (I), in particular of its sodium salt, for the selective control of weeds in crops of cereals, in particular in crops of wheat.
The invention furthermore provides a method for the selective control of weeds in crops of cereals, in particular in crops of wheat, which is characterized in that the compound 2-(2-trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one of the formula (I)xe2x80x94abovexe2x80x94and/or salts of the compound of the formula (I), in particular its sodium salt, is/are applied with surfactants and/or customary extenders in crops of cereals.
The compound of the formula (I) and its Na salt are already known (cf. U.S. Pat. No. 5,534,486xe2x80x94Examples 79 and 321).
The compound of the formula (I) and its salts have a broad herbicidal activity. They can be used, for example, for controlling the following weeds:
Dicotyledonous weeds of the orders: Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio, Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum, Rorippa, Rotala, Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis, Papaver, Centaurea, Trifolium, Ranunculus, Taraxacum.
Monocotyledonous weeds of the orders: Echinochloa, Setaria, Panicum, Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus, Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristylis, Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea, Dactyloctenium, Agrostis, Alopecurus, Apera, Aegilops, Phalaris.
However, the use of the compound (I) and its salts is by no means limited to these orders but extends in the same manner to other plants as well.
The compound of the formula (I) and its salts have strong herbicidal activity and a broad spectrum of activity when used on the soil and on above-ground parts of plants. They are suitable for the selective control of monocotyledonous and dicotyledonous weeds in monocotyledonous crops, especially in cereals, in particular in wheat, both by the pre-emergence and by the post-emergence method.
Problematic weeds which can be controlled particularly well with the compound of the formula (I) and its salts, in particular its sodium salt, and whose control is less likely to succeed with both conventional herbicides and more recent compounds of a similar molecular structure are, in particular, Agropyron, Alopecurus, Amaranthus, Apera, Avena, Brassica, Bromus, Capsella, Digitaria, Echinochloa, Erysimum, Lolium, Matricaria, Phalaris, Poa, Polygonum, Setaria, Sinapis, Thlaspi and Veronica.
The compound of the formula (I) and its salts, in particular its sodium salt, can be converted into the customary formulations, such as solutions, emulsions, wettable powders, suspensions, powders, dusts, pastes, soluble powders, granules, suspension/emulsion concentrates, natural and synthetic materials impregnated with active compound, and very fine capsules in polymeric substances.
These formulations are produced in a known manner, for example by mixing the active compounds with extenders, that is liquid solvents and/or solid carriers, optionally with the use of surface-active agents, that is emulsifying agents and/or dispersing agents and/or foam-forming agents.
If the extender used is water, it is also possible to employ for example organic solvents as auxiliary solvents. Suitable liquid solvents are essentially the following: aromatics, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatics, such as chlorobenzenes, chlorinated aliphatics, such as chloroethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, for example petroleum fractions, mineral and vegetable oils, alcohols, such as butanol or glycol and also their ethers and esters, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents, such as dimethylformamide and dimethyl sulphoxide, and also water.
Suitable solid carriers are: for example ammonium salts and ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and ground synthetic minerals, such as finely divided silica, alumina and silicates; suitable solid carriers for granules are: for example crushed and fractionated natural rocks such as calcite, marble, pumice, sepiolite and dolomite, and also synthetic granules of inorganic and organic meals, and granules of organic material such as sawdust, coconut shells, maize cobs and tobacco stalks; suitable emulsifying and/or foam-forming agents are: for example non-ionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, for example alkylaryl polyglycol ethers, alkylsulphonates, alkyl sulphates, arylsulphonates as well as protein hydrolysates; suitable dispersing agents are: for example lignin-sulphite waste liquors and methylcellulose.
Tackifiers such as carboxymethylcellulose and natural and synthetic polymers in the form of powders, granules or latexes, such as gum arabic, polyvinyl alcohol and polyvinyl acetate, as well as natural phospholipids, such as cephalins and lecithins, and synthetic phospholipids, can be used in the formulations. Other possible additives are mineral and vegetable oils.
It is possible to use colourants such as inorganic pigments, for example iron oxide, titanium oxide and Prussian Blue, and organic dyes, such as alizarin dyes, azo dyes and metal phthalocyanine dyes, and trace nutrients such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc.
The formulations in general contain between 0.1 and 95 per cent by weight of active compound, preferably between 0.5 and 90%.
For the control of weeds, the compound of the formula (I) and its salts, as such or in the form of their formulations, can also be used as mixtures with known herbicides, finished formulations or tank mixes being possible.
Possible components for the mixtures are known herbicides, for example amidosulfuron, bentazon, bromoxynil, carfentrazone(-ethyl), cinidon(-ethyl), clodinafop(-propargyl), clopyralid, chlorsulfuron, chlortoluron, cyclosulfamuron, 2,4-D, diclofop(-methyl), difenzoquat, diflufenican, florasulam, flupyrsulfuron(-methyl, -sodium), pyraflufen(-ethyl), ethoxyfen, fenoxaprop(-ethyl), fluoroglycofen(-ethyl), flupropacil, fluroxypyr, iodosulfuron, isoproturon, mecoprop, metosulam, metribuzin, metsulfuron(-methyl), pendimethalin, prosulfocarb, pyridate, sulfosulfuron, thifensulfuron(-methyl), tralkoxydim, triasulfuron, tribenuron(-methyl), trifluralin.
Mixtures with other known active compounds, such as fungicides, insecticides, acaricides, nematicides, bird repellents, plant nutrients and agents which improve soil structure, are also possible.
The compound of the formula (I) and its salts can be used as such, in the form of their formulations or in the use forms prepared therefrom by further dilution, such as ready-to-use solutions, suspensions, emulsions, powders, pastes and granules. They are used in the customary manner, for example by watering, spraying, atomizing or scattering.
The compound of the formula (I) and its salts can be applied either before or after emergence of the plants. They can also be incorporated into the soil before sowing.
The amount of active compound used can vary within a substantial range. It depends essentially on the nature of the desired effect. In general, the amounts used are between 1 g and 1 kg of active compound per hectare of soil surface, preferably between 5 g and 0.5 kg per ha.
The use of the compound of the formula (I) and its salts can be seen from the following examples.
In the use examples, the compounds shown below are used as comparative substances: 
2-(2-Trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-ethyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one (known from EP-507 171, U.S. Pat. No. 5,534,486xe2x80x94Example 87) 
2-(2-Trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-methyl-5-ethoxy-2,4-dihydro-3H-1,2,4-triazol-3-onexe2x80x94sodium saltxe2x80x94(known from U.S. Pat. No. 5,534,486xe2x80x94Example 260) 
2-(2-Trifluoromethoxy-phenylsulphonylaminocarbonyl)-4-methoxy-5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (known from EP-422 469xe2x80x94Example 96; see also U.S. Pat. No. 5,057,144xe2x80x94Example 96) 
2-(2-Trifluoromethyl-phenylsulphonylaminocarbonyl)-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-onexe2x80x94sodium salt (known from EP-507 171, U.S. Pat. No. 5,534,486xe2x80x94Example 187) 
2-(2-Difluoromethoxy-phenylsulphonylaminocarbonyl)-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-onexe2x80x94sodium salt (known from U.S. Pat. No. 5,534,486xe2x80x94Example 319) 
2-(2-Chlorodifluoromethoxy-phenylsulphonylaminocarbonyl)-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-onexe2x80x94sodium salt (in the claim of EP-507 171 and U.S. Pat. No. 5,534,486) 
2-[2-(1,1,2,2-Tetrafluoroethoxy)-phenylsulphonylaminocarbonyl]-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one (in the claim of EP-507 171 and U.S. Pat. No. 5,534,486) 
2-[2-(Pentafluoroethoxy)-phenylsulphonylaminocarbonyl]-4-methyl-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-onexe2x80x94sodium salt (in the claim of EP-507 171 and U.S. Pat. No. 5,534,486)